package com.canopys.study.open.test.designpatterns.observer;

/**
 * @Author: Canopys
 * @Descrption:
 * @Date: Created in 21:33 2019/11/7
 * @Modified By:
 */
public interface Subject {

    void register(Observer observer);

    void remove(Observer observer);

    void notify(String state);
}
